A suicide bomber detonated a pickup truck loaded with explosives outside a market, killing at least 32 people in a town claimed by both the Iraqi government and the Kurdish region.
Iraqi police and hospital officials said the powerful explosion Tuesday evening in Tuz Khormato wounded at least 75 people.
At least six members of Iraq's security forces were among those killed. Tuz Khormato is about 130 miles north of Baghdad.
The town has long been the scene of skirmishes between Kurdish fighters known as the peshmerga and the mostly Shiite militia forces loyal to Baghdad.
These clashes escalated following the Kurdish region's independence vote in September.
No one immediately claimed responsibility for the attack.
The Associated Press contributed to this report.